SumatraPDF new features: June 22, 2026

New in the SumatraPDF pre-release builds:

SumatraPDF can open and view Markdown documents (.md, .markdown), rendered as formatted text with GitHub Flavored Markdown (tables, task lists, strikethrough). The installer registers the file association. This comes with an update of the MuPDF rendering engine to 1.28.

PDF forms can be filled in directly: click checkboxes and radio buttons, type into text fields in place, pick values from combo boxes and list boxes, and move between fields with Tab / Shift + Tab. Form calculations written in JavaScript run; turn PDF JavaScript off with the new DisableJavaScript advanced setting. Filled forms are saved like annotations, and the close prompt now says “Unsaved changes”.

Right-clicking a tab whose document has unsaved changes (filled forms, new annotations) shows Save changes to existing PDF, Save changes to new PDF and Discard changes at the top of the menu.

The Find bar has a new Match whole word toggle next to Match Case, so searching cat won’t match category (CmdFindToggleMatchWholeWord) (#4295).

Find-as-you-type now waits briefly after you stop typing before searching (500 ms, or 1 s for 1-2 characters) instead of searching on every keystroke. Press Enter to search immediately (#4626).

New Go to Next Favorite and Go to Previous Favorite commands (CmdGoToNextFavorite, CmdGoToPrevFavorite, Ctrl + K command palette) jump to the nearest favorite page after or before the current page (#3744).

You can paste an image from the clipboard into a PDF as an image stamp annotation: right-click → Annotations → Create Under Cursor → Image From Clipboard, or Create Image Annotation From Clipboard (CmdCreateAnnotImageFromClipboard) in the command palette. The stamp is placed at the click point and selected so you can move or resize it (#3671).

More: changes from June 22, 2026 and the full changelog.